It is common practice in dental offices to use the same handpiece, e.g., dental drills, in the mouths of all patients. Accordingly, it is important that the handpiece be scrupulously clean to avoid the transmission of disease from one patient to the next. However, modern dental instruments are complex, high precision tools which are difficult to sterilize between patients. Because such high precision instruments are expensive, it is impractical for a dentist to have a sufficient number of sterilized handpieces to accommodate all of his patients.
For the above reason, dental handpieces are usually disinfected between each patient by simply wiping the instruments with a disinfectant such as alcohol. The drawback to this approach is that it does not sterilize the instruments. Moreover, such disinfectants may irritate the skin of the patient.
U.S. Pat. No. 4,266,935 to Hoppe discloses an elastic tubular casing that can be pulled over a dental tool such as a drill or the like to protect it from infectious agents. The casing comprises a protective ring made of hard synthetic resin located at the working end of the dental tool through which the burr extends. The casing is said to be disposal.
U.S. Pat. No. 2,073,137 discloses a sanitary cover similar to that of Hoppe, except that the protective ring is made of metal. Upon removal, the cover may be sterilized by usual methods.
A drawback of the sanitary covers disclosed in the above references is that the covers or casings are of a complex design comprising two dissimilar materials joined together. Such covers are expensive to manufacture. Moreover, because the covers contain a rigid portion, they must be designed for a specific instrument. This means that their use is severely limited.